Mechanical stage for microscopes



1950 B. G. GALLASCH MECHANICAL STAGE FUR MICROSCOPES Filed Dec. 24, 1946 FIG.I

: FIG.2

{as GALLASCH 3maentor PIC-3.9

(Ittorneg Patented Dec. 26, 1950 MECHANICAL STAGE FOR MICROSCOPES Bernhardt George Gallasch, Rochester, N. 'Y., as.- signor to Bausch .& Lomb ()ptical Company, Rochester, Y., a corporation of New York Application December 24, 1946, Serial No. 718,233

1 Claim.

The present invention relates to improvements in microscopes and more particularlyit has reference to mechanical stages by which specimens are moved across the stage of a microscope.

Many of the delicate tasks performed by pmicroscopists require a mechanism for moving .the specimen which is capable of minute movements in a smooth and reliable manner. How- .eyer, when the slides andjournals of the traversing mechanism are closely and accurately fitted, this requirement is difiicult to attain and very often the action is characterized by abrupt or jumpy starts. Moreover, when the arm of the mechanical stage is moved across the stage surface, the friction therebetween is detrimental to Further objects of this invention are toprovide an adjustable antifrictional bearing for supporting one end of 'a mechanical stage arm on the stage and also to provide mechanism for moving the arm in a smooth and even manner.

These and other objects and advantages will :be apparent by reference to the following .description and accompanying drawing in which:

Fig. 1 is a fragmentary view at a reduced scale of a microscope showing a preferred embodiment of my invention mounted thereon,

Fig. 2 is a top view of the stage of a microscope with a mechanical stage mechanism mounted thereon,

Fig. 3 is a sectional view at an enlarged scale taken on the line 3--3 of Fig. 2,

Fig. 4 is a sectional view at an enlarged scale taken on the line 4-4 of Fig. 2,

Fig. 5 is a sectional view at an enlarged scale taken on the l ne 5-5 of Fig. 2,

Fig. 6 is a sectional view at an enlarged scale taken on the line 66 of Fig. 2,

Fig. 7 is a sectional view at an enlarged scale taken on the line I'| of Fig. 2,

v Fig. 8 isa sectional view at an enarged scale taken on the line 88 of Fig. 2, and

Fig. 9 is a sectonal view at an enlarged scale taken on line 9-9 of Fig. 8.

A microscope embodying a preferred form of my invention is illustrated in the drawing in which the numeral ll designates a microscope stand having a stage I2, on the upper surface l3 of which a specimen is held for exam'nation. Extending through the stage [2, an opening I4 is provided over which the specimen is placed ill 'the stage.

between.

for examination so that it will be transilluminated by light rays projected from underneath It will be understood that the usual optical system, not shown, for illuminating and forming an enlarged image of the specimen is part of the microscope shown in Fig. 1.

On the stage 2 a mechanical stage mechanism is provided for moving the specimen across the stage surface it comprising a mounting plate It secured by any suitable means such as screws it: against the vert cal straight edge I! of the stage. A rail It held by suitable means such as screws 19 against the mounting plate l5 has a sliding head, 21] traversably mounted thereon. Rail i3 is preferably of dovetailed shape in cross section as shown in Fig.3 and a corresponding dovetailed groove 2| loosely fitting the rail 18 is formed in the head 20. Lost motion between the rail l8 and groove 2! is taken up by a flat .norma'ly-curved spring 22 confined in the clearance space between the rail and groove.

Secured to the head by suitable means, not

shown, is an arm Z3.extending across the surface l3 and being free at the outer end, said arm having a bar 24 slidably mounted thereon. The

slidable connection between the arm 23 and bar 23 is of similar construction to that shown in Fig. 3. As best shown in Fig. 4, the slidable bar .2 is provided with a dovetailed rail 25 loosely fitting a groove 26 in the arm 23 and having a flat spring 21 held in the clearance space there- Specimen holders 28 and Y29 which, as shown n Fig. 2, are particularly adapted to hold a specimen plate, not shown, are fixed to the slidable bar 24.

For moving the specimen in a fore and aft direction parallel to the mounting plate I5, the rail 1 8 has a rack 30 fixed thereto by any suitable means, such as screws 3|, and has a pinion, not shown, meshed therewith which is rotated by a knob 33. Movement of the specimen in a crosswise direction is accomplished by a rack 34 attached to the bar 24 and meshing with pinion 35 which is journaled by a shaft 36 in the arm 23. A knob 3'! is attached to the shaft for rotating the pinion 35. The shaft 36 is journaled in a two-part bearing, one part of the bearing being formed in the arm 23 and the opposite part being formed in a pillow block 38 that loosely fits within a recess 39 in the arm 23.

In this type of bearing, the complementary parts are usually tightly assembled together creating in effect a solid bearing. In the present device, however, the looseness of the fit of the pillow block 38 within the recess 39 permits the bearing surfaces of the block to properly align with the opposite bearing surfaces thus eliminating any binding side pressure. An arched fiat spring 40 seated on top of the pillow block 38 is selectively stressed by an adjustment screw 4| to resiliently press the block 38 with any desired pressure against the shaft 36. Openings 42 and 43 in the pillow block 38 and spring 48, respectively, are provided through which a suitable lubricant may be forced by first removing the adjustment screw 4| and inserting a lubricant nozzle in the screw hole. The overall advantage to be gained by this construction of the bearing and its adjustment mechanism is the great reduction in static bearing friction which opposes initiation of rotation of the shaft, thus insuring a smooth start of the rotation of the shaft.

An outstanding feature of m invention is the antifrictional bearing preferably in th form of a roller 44 by which the free end of the arm 23 is supported slightly above the surface [3 so as to prevent sliding friction from interfering with the smooth and easy movement of the arm. Roller bearing 44 is rotatably mounted on an axle or journal pin 45 extending crosswise of a narrow slot 46 formed in the arm 23 for housing the roller. Journal pin 15 has an enlarged cylindrical body portion t1 extending integrally and eccentrically therefrom constituting an adjust ment means therefor, said body being rotatabiy mounted in a bore 48. The amount of projection of the periphery of the roller it below the undersurface of the arm 23 ma be changed by rotating the body 41. Any desired means of rotating the body portion 4'! may be provided such as a screw driver slot 39 extending across the end surface of the body portion.

In order to lock the roller journal pin :35 in the proper operative axial position and desired rotational setting, an annular V groove 50 is formed in the cylindrical surface of the body portion 41. A set screw 5i having a tip which is pointed to fit the groove 50 and is arranged in alignment therewith cooperates with the groove in the body 41 to provide the locking means for the axle pin 45, since the pin is integral with body 41.

An arm guide 52 having a hook-like extension beneath the stage I2 is fixed in any desired manner to the free end of the arm 23 to prevent the arm from being lifted vertically awa from the stage I2.

When it is desired to change the clearance between the arm 23 and surface 13, the locking screw 5! is first loosened, a screw driver is inserted into the slot 49 through an aligned clearance opening in the arm guide 52 and the axle or journal pin 15 is thereby rotated until the projection of the roller bearing 44 below the arm 23 has been correctly set. Then the locking screw 5| is again tightened.

It will be seen that the mechanism provided by this invention promotes a smooth and even action of the mechanical stage mechanism wherein abrupt starts are avoided. The advantageous construction of the sliding connections, shaft bearings and in particular the arm-supporting roller 44 causes reduction of the effects of static and sliding friction to a minimum.

Although. but certain forms of the invention have been shown and described in detail, these forms are not exclusive and changes may be made in the form and arrangement of the part and substitutions may be made without departing from the spirit of the invention as defined in the appended claim.

I claim:

A mechanical stage positioned on the upper surface of a microscope stage comprising an overhanging arrn having a, free end adapted to be moved along said surface, a rotatable bearing member projecting from said arm and contacting said surface to space the arm from said surface, a journal pin on which said bearing member rotates, said pin having a cylindrical eccen tric surface integral therewith by which said pin is mounted within a bore in the arm, and locking means for holding said eccentric surface and pin in a stationary position longitudinall and rotationally.

BERNHARDT GEORGE GALLASCI-I.

CITED The follor-Jing references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 536,552 Swift Mar. 26, 1895 588,689 Bausch Aug. 24, 1897 878,031 Adams Feb. 1, 1908 898,957 Watkins July 21, 1908 1,007,978 Sauveur Nov. 7, 1911 1,188,316 Pierce June 20, 1916 1,798,634 Schafer Mar. 31, 1931 1,811,508 Klages June 23, 1931 1,974,606 Fassin Sept. 25, 1934 

